1. Field of the Invention
The invention relates to a display device mountable in e.g. a vehicle-mounted navigation system for displaying different images in multiple directions. More specifically, the invention relates to a device that controls an operation based on which direction of the display device the operation was performed from.
2. Description of Related Art
Japanese Laid-Open No. 2000-36927 for example proposes a vehicle-mounted navigation system as a conventional display device that displays different images in multiple directions. On the other hand, Japanese Laid-Open No. 2004-67031 proposes a vehicle-mounted navigation system that restricts an operation by detecting which direction the device was operated from, even though this device does not display multiple images.
Japanese Laid-Open No. 2000-36927 describes a device that displays multiple images in different directions by lenticular lens and a parallax barrier, or by a display device that alternately displays temporally varying images and glasses that alternately perform light transmittance and light shielding. This device makes it possible to display to the passenger's seat side an image without being restricted by the driving status.
Japanese Laid-Open No. 2004-67031 describes a device in which an infrared camera is positioned to capture an image of an operating unit of a vehicle-mounted navigation system, and the device detects which of the driver's seat direction or the passenger's seat direction the operation was performed from, based on the position of the hand of the operator during the operation. This device thus partially prohibits an operation from the driver's seat side. This device makes it possible to partially restrict only an operation from the driver's seat side and eliminates restriction on the operation from the passenger's seat side.
However, Japanese Laid-Open No. 2000-36927 suffers a limitation that an operation means for the driver's seat side image and an operation means for the passenger's seat side image had to be provided separately, which was confusing to an operator due to the increased operation buttons and which also increases the device size. Even though the device described in Japanese Laid-Open No. 2004-67031 may restrict an operation from the driver's seat side, the device does not restrict displaying an image that interferes with driving, such as a TV image or long text to the driver's seat side.